In comparison with conventional mechanical locking devices, such electronic locking devices have large merits in security and are widely used in facilities where many locking devices are required such as hotels. However, the electronic locking devices now in use in hotels and the like require issuance of a fresh magnetic card whenever a user such as a guest of a room changes, the fresh card having a code differing from those of the former users and also differing from those of other rooms. Accordingly, an expensive card issuing machine is required as well as considerable time and trouble.
Most safes installed in guest rooms of hotels and the like are provided with mechanical locking devices. Even if electronic locking devices are installed on doors of such rooms, separate keys are required for the safes. The management of such keys are troublesome and the advantages of the installation of electronic locking devices on the doors are reduced.
The present invention has been made with this in mind and it is an objective to provide an electronic locking device which requires no card issuing machine, has low installation and running costs, and is simple in operation.